1. Technical Field
The present invention relates to medical devices, and more particularly, to a bolster assembly for maintaining a medical interventional device, such as a gastrostomy tube or a jejunostomy tube, in position along a body surface of a patient.
2. Background Information
Patients for whom normal ingestion of food becomes difficult or impossible may require placement of a feeding tube to assist in providing their nutritional needs. For some individuals, such as comatose patients, stroke victims, or those with a compromised gastrointestinal tract, this may require introduction of a feeding tube for delivery of nutritional products directly into the stomach or the jejunum. Tubes for delivery of nutritional products into the stomach are generally referred to as gastrostomy tubes, or “G”-tubes. Tubes for delivery of nutritional products into the jejunum are generally referred to as jejunostomy tubes, or “J”-tubes. In many cases in which a J-tube is utilized, the J-tube is inserted through the interior of a previously positioned G-tube.
There are two general methods for percutaneously positioning a gastrostomy tube in a patient. One such method, referred to as the Ponsky, or “pull”, method involves introduction of an endoscope through the patient's mouth and esophagus and into the stomach. The endoscope contains a light source having sufficient power such that the position of the endoscope can be visualized on the outside of the patient's abdomen. A needle is then inserted through the abdominal wall and is visualized by the endoscope. A wire guide is passed through the needle and is grasped by the endoscope and pulled up through the esophagus and out through the mouth. The wire guide is then fastened to the end of the gastrostomy tube, and pulled back down through the esophagus and stomach. The leading end of the wire guide and the external portion of the gastrostomy tube are pulled out through the aperture in the abdominal wall initially formed by the needle. Typically, an internal bolster, such as a balloon, is provided internal of the stomach to hold the stomach against the abdominal wall, and an external bolster is provided external of the abdomen for anchoring the device exterior of the patients skin.
The other method is commonly referred to as the “push” method. In this method, the endoscope is used to provide the physician with a visual indication of the stomach, and a needle and wire guide are inserted into the stomach through the abdominal wall utilizing, e.g., the well-known Seldinger percutaneous-entry technique. In this technique, following withdrawal of the needle, the physician inserts, or pushes, the gastrostomy tube through the abdominal wall over the wire. The tube may be anchored with internal and external bolsters in the manner described above. Following placement via either of these two methods, proper positioning of the internal bolster against the stomach wall may be confirmed with the endoscope.
Feeding tubes used in long-term enteral feeding are generally made from an inert, biocompatible medical grade material such as silicone rubber or polyurethane. Such tubes are generally soft and flexible, so that they do not cause undue discomfort to the patient. In an attempt to eliminate the discomfort and inconvenience of a perpendicularly-extending tube, such tubes are often flexed over at a right angle, in a manner such that the tube is taped down on the skin surface. One problem with this arrangement is that such tubes have a tendency to kink at the point where the tube is flexed over at the right angle. Repeated flexing of the tube at the juncture as it exits the bolster creates continuous stress at the flexure point. This action weakens the tube, and increases the possibility that stress fractures and cracking of the tube wall may occur, which actions may lead to premature failure of the device. This is especially true in smaller diameter tubes, such as the 18 French, or smaller, tubes used with pediatric patients. These smaller size tubes often also have thinner walls, which makes them even more susceptible to premature failure from repeated flexing of the tube. In addition, when tape is utilized to tape the tube to the skin surface, the removal of the tape tends to leave a residue on the skin of the patient. Such tape is also difficult to clean, painful to remove, and erosive to the skin.
It would be desired to provide an external bolster assembly for an interventional medical device that overcomes the problems of prior art devices.